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Shop Solutions: Faucet Parts Gush from Multistation Center

A manufacturing engineer’s open mind, common sense and eclectic background in business have transformed the way parts are machined at the Guadalajara, Mexico, plant of plumbing fixture leader URREA Group. Charged with re-inventing a process that relied on discrete machining centers to cut brass faucet components at rates of 10 parts an hour, Project Director Juan Ramon Delfin Madariaga studied technology from around the world before settling on an entirely different concept—the ICON 6-250 from Hydromat Inc. (St. Louis).

The ICON 6-250 is a single, multiple-station machining center with four CNC spindle modules, which has taken on all the production for five part numbers, while using only 60% of its capacity. The machine’s ability to produce the same parts at rates up to 350 plus per hour, with higher quality and process capability, is at the heart of URREA’s strategy to re-shore parts made in Asia and expand the company’s already substantial market coverage to the entire globe.

URREA Group is a diversified, family-owned Mexican company focused on three key markets: bath environments, hydraulic components, and locksmith tools and solutions. Its plumbing brands include URREA, Stanza, Orion, and Dica. The company’s business campus in Guadalajara occupies more than 248,900 m2 and continues to grow.

Madariaga was tasked in 2011 with redesigning the machining processes for multiple faucet parts. “We were using three high-quality horizontal machining centers to cut the parts, fixtured two-up, and we were producing about 10 per hour,” he said. “The company needed a process that would allow us to start at lower volume, and increase gradually. We also wanted to reduce the piece cost, and be able to change over quickly, because over time we hope to transition to a high-volume, just-in-time manufacturing operation, to the extent that’s possible in our business.

“My policy is to break from the old ways and rules, and use rational thinking to find a new path,” said Madariaga. “The obvious and standard solutions are not the best for everyone. For example, one of the German machines we considered needed a day to change the process. We were focused on the best European machines, not the US, but the best solutions are not always in the obvious places.”

The presentation on the ICON machine from the local Hydromat contact came at just the right time, according to Madariaga. “Hydromat assured us the ICON 6-250 machine could easily handle our parts and would surprise us. We visited St. Louis in September, saw the ICON machine in action and evaluated the process strategies Hydromat had developed for our parts.”

The ICON 6-250 is capable of having both horizontal and vertical working spindles at the same position. It enables some unusual processing strategies, so it caught the attention of an outside-the-box thinker like Madariaga. The ICON 6-250 machine can handle parts up to 250-mm cube and is designed for medium to high-volume, flexible part production. The single machine incorporates eight individually controlled three-axis spindle modules, four horizontal and four vertical, with a full fourth-axis interpolation indexer at each of the four machining positions.

Spindles are arranged in pairs of one horizontal and one vertical at the four machining positions, which are on the perimeter of the six position pallet-transfer. The four machining positions are equipped with CNC B-axis indexers capable of ±4 arc-sec accuracy, while the two nonmachining stations are fixed position, one to be used for part loading and the other used for gaging, assembly, part ID marking, etc. Both nonmachining stations can also be used simply for part loading. A cycle for the pallet-transfer takes just 4.5 seconds, with each pallet handling up to 91 kg standard. The pallet system uses zero-point clamping to securely and accurately clamp the 300-mm base pallet to the indexer.

Each HSK A63 spindle has its own 12-position disk-style toolchanger unit, with each tool change done in a rapid 3.5 seconds. A fully equipped ICON with eight machining units has a total inventory of up to 96 tools. The disk allows direct toolchange without a cam box or toolchange arm, eliminating frequent maintenance issues.

The machine can put up to eight spindles into the cut at one time, performing five-sided machining on four different parts at one time, all in a single clamping. Flexibility is enhanced with Fanuc standard programming, standard or special tooling, and fixturing typical of any horizontal/vertical machining center. The machine is completely self-contained with coolant system, hydraulics, PLC and CNC electrical systems—the equivalent of eight CNC machining centers in a footprint of just 54 m2.

For URREA’s first part numbers, two brass faucet spouts, Hydromat developed a four-position tombstone-like fixture with hydraulic clamping and interchangeable form jaws. The form of the upper jaw provides the locating point for the part, so it is protected during loading from chips/contaminants. With this process concept, four parts are completed on every table index, with 20 parts in the workzone at all times. Operations on the parts include drilling, thread milling, tapping, counterboring, face milling, and chamfering. Each of the four machining stations performs different operations, further enhancing the machine’s output rate.

Hydromat developed two different processing approaches for URREA’s first two part numbers. The difference involved part load/unload from one station or two. In one case with load/unload at a single station, the machine completes four parts on every table index with a cycle time 60 seconds, or about 15 seconds per part. When loading/unloading from two stations the machine completes eight parts on every table index in 91 seconds, or just under 12 seconds per part. The potential output of the machine proved so aggressive that URREA initially set the machine up for loading from only one station.

Installed in March 2012, the machine today handles five different part numbers, all of which can be machined in the same fixture, but with different form jaws. Changeovers on the machine—currently about five per week—take about an hour to 90 minutes.

“When the machine was first delivered, the first two things I noticed were its heavy construction and the precision of the machining technology,” said Luis Manuel Galan Vicente, project manager. “It has proven exceptionally accurate.

“The machine has been a strong performer, and we are gradually adding part numbers to exploit its potential,” said Vicente. “The throughput per square meter makes it the top production asset on our factory floor. It’s like a factory within our factory. This machine, and probably more like it, will play a key role in the expansion of our worldwide market coverage and re-shoring work to North America.” ME

For more information from Hydromat Inc., go to www.hydromat.com, or phone 314-432-4644.

This article was first published in the November 2013 edition of Manufacturing Engineering magazine. Click here for PDF.